Saturday 15 November 2014

Teachers launch weather balloons, and a passion for science



A weather-balloon kit helped two teachers inspire their students with custom experiments.

 

Making science, technology, engineering and math into hands-on endeavors can spark interest in these fields and cement concepts learned in the classroom. As science coordinator and a physics teacher at Harrisonburg (Va.) High School, Andy Jackson* was looking for a good, complex hands-on project for sophomores and juniors in the school’s Governor’s STEM Academy. Jackson and the so-director of the STEM academy, Myron Blosser*, came across a hands-on project in May when they visited the National Science Teachers Association STEM Forum and Expo in New Orleans, La.

They ran across a company that offers high altitude weather balloon kits. Made by Stratostar, the kits come with boxes to hold a payload of experiments. Transmitters will send data from the experiments and information about the balloon’s location back to the ground. Jackson and Blosser purchased a package, and two other teachers in the science department, Christina Welsh and Kasey Hovermale headed up the project with their students.

After more than seven weeks of preparation, their students launched their first balloon flight last week. It lofted a 2.7 kilogram (6 pound) payload to 25,908 meters (85,000 feet) and carried it 78 miles west of their launch site. The project gave the students a chance to decide what experiments to send, and to place the cameras and sensors in the payload themselves. The data will be used to design and carry out future flight experiments based on the temperature, sound and humidity data they obtained.

“When we saw this weather balloon idea, we thought ‘This is it,’” Jackson says. “We needed something that would integrate different disciplines. This tied in atmospheric science, chemistry and engineering.”

What they do…


These weather balloons — between 0.7 and 2.4 meters (2.5 to 8 feet) in diameter — work on a fairly simple principle. The balloon is attached to a small payload (less than 5.4 kilograms), filled with helium and released. In short order, it rises into near space, an altitude of between 19,812 and 99,974 meters. As the balloon rises, the atmospheric pressure falls. This causes the helium in the balloon to expand. When the balloon gets high enough, the expanding gas makes it pop. The science payload now falls back to Earth, aided by a small parachute. Meanwhile, the sensors send data on the payload’s location back to the ground, so that teachers can send out search parties to pick it up.



The experiment is more than just a way to measure the ideal gas law. During the balloon’s journey, sensors in the payload collect data and transmit it to students on the ground. Classrooms can put any number of experiments into the payload, as long as the final total weight comes in under 5.4 kilograms.

Jason Krueger, Stratostar’s founder, says he’s helped students and teachers put everything from Geiger counters to tardigradesinto the foam coolers that carry the balloon’s instruments. “We can record sound pulses from a beeper as the balloon travels upward, and measure how the speed of sound changes as you move through the atmosphere,” he says. Classrooms can study particles and radiation, or measure weather features, such as temperature, pressure and humidity. “All of these experiments have sensors that can plug in to our modules and transmit the data down in real time,” Krueger says.

Video cameras can record the journey, as well as providing live feed as sensors collect data. “It makes the whole thing a lot more meaningful than just taking a problem from a book,” Krueger says. Stratostar offers programs to that take students through generating hypotheses to designing and launching experiments. Those experiments can be tailored for elementary, middle- and high-school classrooms.

That said, these balloon packages come with a hefty price tag. Krueger says that packages start at around $12,000. Jackson estimates his team spent $15,000. Each package comes with extensive training from Krueger and others on the team, who travel out to each school to aid the students. And the payloads can be used over and over again with new balloons.

Each individual flight costs about $500 in materials. Jackson and Blosser were lucky enough to get a grant award from the Aluminum Company of America, which picked up the costs of the program. But without that funding, the balloons might exceed a school’s teaching and materials budget. Right now, Stratostar is also limited to working within the United States.

The customizable aspect of the ballooning experiments drew in Jackson and Blosser. Their students were inspired, as well. “As the deadline approached [the balloons require certain weather conditions to fly and cannot be released in winter], the kids and teachers were at school on Sunday afternoon and on teacher’s workdays,” says Jackson. “They really wanted to make it happen.”

As the launch approached, the weather chose not to cooperate. With winds coming in from the wrong direction, releasing the balloon at the high school could have resulted in a payload lost at sea. Then the student’s desire to see the project to completion really came through. They “did the leg work to try and figure out where we could go to do the launch and how it would have to work.” In the end, the students scouted out and designated a new launch site. The balloon flew from Bath County Airport, more than 160 kilometers from the high school, where the wind would blow the payload west toward the mountains, instead of east towards the ocean.

Because of the students’ hard work, the launch was a success and the payload was retrieved successfully. Jackson and Blosser are looking forward to working with the students to analyze the data from the first flight and make plans for future cloud-based tests.
*Andy Jackson was my high school physics teacher. Myron Blosser was my advanced placement biology teacher. I attended Harrisonburg High School from 1996 to 2000.